1. Field
Embodiments relate to a method, apparatus, and medium for measuring a distance using a radio frequency (RF) signal, and more particularly, to a method, apparatus, and medium for measuring a distance by which even though an obstacle exists between a signal generating module for measuring a distance and a fixed module and therefore line of sight (LOS) between the two modules is not guaranteed, an RF signal is received, the distance is measured, and existence of an obstacle is determined, thereby improving the accuracy of distance measurement.
2. Description of the Related Art
Mobile robots, such as cleaning robots and security robots, are used in homes or offices. In order to specify a path or region for a mobile robot's movement and to avoid collision of a mobile robot with an obstacle in the region, accurate information on the position of the robot is necessary.
A variety of methods have been studied in order to obtain position information of a robot, and recently a distance measuring module using a radio frequency (RF) has been under development. According to the distance measuring method using an RF signal, a signal generating module generates and transmits a signal of a predetermined frequency, and a fixed module disposed at a fixed position receives the signal and transmits the signal back to the signal generating module. In this way, the distance is measured using the time taken for the signal generating module to receive the signal generated and the speed of the signal.
Unlike other methods, the method using an RF signal can measure distance between two things through transmission and reception of an RF signal even when an obstacle exists between the two things, and therefore line-of-sight (LOS) is not guaranteed. That is, the method has an advantage that it can be used even in an indoor environment where furniture and walls exist.
However, if this method is applied to a mobile robot, an error occurs in measuring the distance due to interference by an obstacle that can exist between a signal generating module disposed in the robot and a fixed module, such as a wall. Accordingly, it is necessary to reduce an error that occurs due to lack of LOS and to increase the accuracy of distance measurement.